Mechanical arm



NOV. 1, 1932. 5, pg so 7 1,885,138

MECHANICAL ARM Filed Sept. 20, 1929 2 Sheets-Sheet l 527M BIL-SON ATTORNEY NOV. 1, 1932. v 5, PILSON 1,885,138

MECHANICAL ARM Filed Sept 20, 1929 2 Sheets-Sheet 2 g fo' INVENTOR ATTORNEY Patented Nov. 1, 1932 SAM :IPILSON, or BEN'1.ON, rnnnv lois Y MECHANICAL ABM Application fi1ed.September 20, 1929.v .SeriaI No .f31'4,'02 8.

This invention relatesto'mechanical artificial arms and more particularly to an-arm designed to be worn by a person, one-0f whose arms has been severed between the handan'd elbow, the primary object of the invention being to provide a device of this class WhlCh will enable the wearer, by a movement ofthe forearm with respect to the upper arm to grasp and hold objects, the device operating automatically upon such movement of the forearm.

Another object of the invention is to provide a device for the purpose stated soconstructed as to'aiford maximum freedom of movement 'of'the forearm to effect coaction-of grippingmembers which take the place of the fingers of the severed hand, and in this connection, the device also has as its object to so mount the gripping members and the operating means therefore as to permit of a considerable rotative displacement of the gripping members about the axis of the forearm unit of the device, thus enabling the wearer of the device to move his arm independently of an article or object grasped and withyrespectthereto. Y

Another object of the invention is to so construct .the same 'tha't the wearer may first grasp an object which'isso positioned that I it would be inconvenient for the wearer to -maintain his hold upon the object dueto an unusual position 1 of the handle-es 'arm and, after grasping the 'ob ect move his arm to a comfortable position :withoutre'leasing the grasp of the arm upon the object.

This invention also consists in certain other features ofconstructlon and in the combinaftion and arrangement of the several parts, to

be hereinafter fully described, illustrated in the accompanying drawings, and specifically pointed out in the appended claims.

In describing my invention in'detail, ref- 'erence will be had to the accompanying drawings wherein like-characters denote like or corresponding partsnt'hroughout *the several views, and in which I Figure 1 is a view in sideelevation illustrating the device embodying the invention and showing the gripping members i and '.as-

sociated parts in full lines, in the'ope-n posidevice. I

iti on of the members and il lustrating the p ositio-ns assumed by the :parts when the membersare closed to grip anobject.

Figure 2 is:a v iewin-front elevationof the Figure 3 is" a detail side elevation of the forward sport-ion of the device illustrating in more detail Lt-he gripping members-and associating parts 1n closed --pos1t;1'on.

Fi'gure leis a detail "view-inside elevationfof one'o'f the gripping menibers. I

Figure 5 is a plan view in detail thereof.

Figure 6 is 'a' perspective 'view of "a link for establishing connection bet ween' the gripping members "and -;the actuatingmeans therefore.

Figure '7 is aview in side elevation and similar to Figure l ill-us'trat-inga modification ofthe invention.

Figure 8 is a top plan view ofthe structure 'shown'in Figure 7.

Figure '9 is 'a detail transverse sectional 'view taken substantially .on the line 9- -9-'of Figure 7.

Figure 10 is a horizontal sectional view taken substantially on the line 10410 of Figure-'9. V

Figure 11 is a fragmentary perspective vlewof a portion of the modified structure shown in Figures? to 10 inclusive.

I The embodiment illustrated in Figuresl to 6 inclusive of the drawings comprises an upper section which is indicated in general by the numeral 1, and consists-essentially of a body of leather or other suitable semiflexible material, which body is indicated -'-by thernumeralflrand.thisibodyiis.of such shape, j both longitudinally and circumferentially,

as to fit around'the upper arm'oflthe wearer ofthe device and, in order that-it mayi'belcon- .veniently adapted to the upper .arm and held securely in placethereon, plurality .of straps .3 are securedto the outer side ofthje body at the front thereof and at one-side of a longitudinal division of .thebody at .the front thereof, buckles 4 being secured to -the o er surf c of theb dY a th th sid of the line in division and thescorresp'ondingstraps and buckles being eadjustably engageable with one another to adapt 'the bodyto be suitably adjusted with a comfortable and yet snug fitting of the same to the upper arm.

The device further includes a lower unit which is indicated in general by the numeral 5 5 which is likewise formed of any suitable relatively rigid material and this body is tapered so as to adapt it to fit about the stump f the forearm. The bodies of the two units are connected by a joint which comprises a pair of hinge members 6, which are riveted or otherwise secured, as indicated by the numeral 7, each to a respective side of the body 2 of the unit 1 and these members, which are preferably in the form of suitable sheet metal strips, are extended below the lower or minor nd of the body 2. Similar members 8 are riveted or otherwise secured to the opposite sides of the body of the unit 5 and extend beyond the upper end of said body and the lower ends of the members 6 and the upperends of the members 8, at each side of the device are arranged in overlapping relation and pivot pins 9 are engaged therethrough so as to provide a pivot joint between the members 1 and 5 at the opposite sides of the elbow of the arm of the wearer. Therefore, in order to provide for perfect freedom of movement of the forearm with respect to the upper arm, the lower end of the unit 1 and the upper end of the unit 5 are spaced at this point. 7

In the embodiment shown in the figures referred to above, the lower end of the unit 5 is closed by a circular metal plate 10 and this plate is formed at diametrically opposite points with pivot ears 11, which project from the plate 10 in spaced parallel relaticnto each other. The gripping members of the device are indicated by the numeral 12, and

each of these members comprises an approximately arcuate body 13 of metal which is of a suitable thickness in cross section to impart to it suliicient strength to enable relatively heavy or fixed objects to be grasped. Each of these members is formed at its rear end with an ear indicated by the numeral 14, and the ears are located at one side of the said end of the respective membersso that the members may be assembled in superposed re lation as shown in Figure 3 of the drawings w th the said earsl l positioned side by side,

.Inatching openings 15 being formed through the ears, and a pivot bolt 16'being secured through the ears 11, above referred to, and through the said openings 15. In this manner two gripping members are m unted upon a common pivot for 'movement toward and fromeach other. In order that the members may more or less firmly grip objects of different nature, each member, in this embodimerit, is formed between its inner and outer ends and in its gripping face with a'recess 17, and the said face, between the forward end of the recess and the extremity of the mem ber is preferably provided with transverse corrugations 18.

Means is of course, provided for effecting automatic opening and closing of the gripping members with respect to each other and this means will now be described.

Secured to each of the hinge members 6 near the end thereof is a plate 19 provided with an upstanding ear 20, the numeral 21 indicating a connecting bar which is pivoted at its rear end to this extension and extends forwardly at the respective side of the unit 5 and is pivot-ally connected with the respective one of the gripping members 12 by means which will now be described. The connecting 2 means referred to preferably in the form of substantially V shaped, relatively short, rocking levers 22, each of which is provided at the juncture of its diverging arms 23 with an opening 24- whereby it is mounted for oscillatory movement upon the bolt 16. The outer end of one of the arms 23 is formed with an opening 25 and a pivot pin 26 is engaged through this opening and through an opening in the extension 20 of the respective one of the members 19. A pivot 27 is fitted through a similar opening 26 formed in the outer end of the other arm 23 and through the respective one of the gripping members 12, and at this point, and particularly by reference to Figure 2, and the dotted line showing of Figure 5, a pair of the rocking levers 22 is provided for the gripping members 12, one of the rocking levers being mounted at one side of the assemblage of the members 12 and the other at the opposite side thereof, and the said members 22 being extended in substantially opposite directions from the pivot bolt 16.

In other words, one of the members 22 is similar connection being established between the downwardly extending rocking lever 22 and the lower gripping member by the other connecting bar 21. 7

From the foregoing description of this embodiment of the invention, and particularly by reference to Figure 1 and the full and broken line illustrations therein, when the forearm of the wearer of the device is lowered so as to be nearly straight with the upper arm, the units 1 and 5' will occupy the relative positions shown in full lines in this figure. It will further be observed by reference to this figure that when the forearm enclosing unit 5 is swung upwardly by the wearer moving the forearm upwardly, at the elbow joint with respect to the upper arm, the rocking lever 22 which is connected with the upper connecting rod 21 for the upper grip member is rocked forwardly so as to swing this gripping member downwardly, and the eas es other rocking gripping member and the outer are properly applied to the bail of the bucket or basket, eflect automatic gripping engagement of said members with the bail and by further upward movement of the arm as a whole, the article may be lifted by the wearer of the device.

It will be understood of course that the downward movement of the forearm or in other words, a straightening of the entire arm, will efi'ect supporting of the gripping members to release the previously gripped object. I

The embodiment of the invention just described embodies no provision for a rotative displacement of the gripping members with respect to the forearm unit, but the modified structure illustrated in Figures '7 to 11 in-,

clusive, does make provision for this movement of the members. In this modified structure the members heretofore described, and indicated by the numerals 1 to 9 inclusive and 12 to 16 inclusive, are indicated by the same reference numerals, primed. In this "11 embodiment, the hinge members 6 and 8 correspond to the members 6 and 8 of the first described embodiment in which they are connected by the pivot bolt 9, in the modified structure, instead of employing the members of the previously described structure, the hinge members 6' and 8 are provided each at its rear end with an outstanding arm 29 which takes the place of the said levers 21 as in the previously described embodiment, the gripping members 12 are provided, each with an arm 30, relatively short in length and extending in the instance of one of the members in an upward direction and, in the instance of the other member in a downward direction, and connecting members 31, corresponding to the members 21 of the previously described structure, are employed in connecting the arms 29 and 30. r

The gripping faces of the members 12' in the modified structure, are preferably provided each with two or more recesses 32 corresponding to the recesses 17 in the gripping of the forearm unit 5, there is provided at the forward or lower end of the body of the forearm unit 5 a closure of circular form iindiicated byithe numeral 33 and provided at one side with a peripheral flange 34 fitted fwithin the saidend'ofthe unitx5 and secured by rivets or other suitable fastening means, 70 the said :clo'surea33wbeing provided at its outer side with an outstanding peripheral flange 35 having its marginal :portion turned inwardly to provide-a circumferential shoulder 36. WVithin the closure'33 there is arranged a ffi rotatable :supporting member 37 which is :p rovi-ded with a marginal flange38, and this member is connected with the member 33 at the axes-of the two members byra pivot 39,

the out-er'side .of the flange .38 fitting withi efio the-circumference of the'flange 35; The numeral "40 indicates two bracket members which are secured by rivets or-otherwise as at 41-to the body of the 'member37 at diametrically opposite sides of-the pivo t39,.and equally distantly spaced therefrom, and these bracketzmembers extend forwardly and the equivalent of the pivot bolt 16 previously described andindicated in these figures, by the numeral '16, is fitted through ears 14 corresponding-to theears 14 and the gripping members 12 are in this manner vsupported in substantiallythe same manner as the grip ping members 12 as described in the first embodiment. It will-be evident at thispoint that the means provided for openin and closingtthe-gripping members 12 is substantially identical withTthe previously described means except that it is somewhat simpler in formand a more direct motion is imparted to the gripping members. In this latter embodiment a detent member 42 is pivotally V mounted at one end as at 43 at therear or inner side of the closure 33 and extends for-v wardly througha slot or opening 44 formed 7105 therein,-and the forward end of this detent member is swung outwardly to provide a lug 45 whichis held in engagement with the inner side of the flange 35 through the medium of a spring 46 which is mounted upon' l10 the pivot 43 for the detent 42. Extending from the end of the lug 45 is a stem 47 which works in a slot 48 extending substantially circumferentially in the flange 35, this flange being formed with a notch 48' which extends between each of the flanges 38 and connects with the slot 48 at a point midway between the ends of the said slot, and it will now be evident that by gripping a head 49, which is provided at the outer end of the stem 47, this being done, of course, by the use of the hand of the other arm of the user, the user may .press inwardly against the detent 43 so as to disengage the lug 45 from the said notch, the lug being normally located in the lock, and, by moving the detent in one direction or the other may rotate the supporting member 37 to correspondingly turn the gripping members 12 about the axis of the unit 5.

Itwill be understood of course that the supporting member may be turned in either di- 1 rection and, after it is not longer required that the gripping members be held ,in-the turned position, the members may be rotated in the backward direction until the spring 46 causes the lug 45 to again engage in the notch 48.

What I claim is 1. A mechanical arm comprising an upper arm unit, a forearm unit, said units being hingedly connected together, jaws pivoted to the end of the forearm unit, extension lugs mounted upon the upper arm unit and a pair of bars, both of said bars being pivotally connected each with one of the lugs at a point to one side of the point of pivotal connection between the upper and forearm units, one of the said bars being pivotally connec ed with one of the jaws at a point at one side of the point of pivotal connection of the jaws with the forearm unit and the other bar being pivotally connected with the other jaw at the opposite side of the point of pivotal connection of the jaws with the forearm unit.

2. A mechanical arm comprising upper and forearm units, pivotally connected together, lug members mounted upon the upper arm unit, jaws pivotally connected with the forearm unit, rocker arms pivoted to the forearm unit at the point where the jaws I are pivoted to said unit, said rocker arms having angularly disposed end portions, the outer end portions of the rocker arms being pivotally connected with the jaws and rods pivotally connected at one end with said lugs and pivotally connected at their other ends with the inner end portions of the respective rocker arms which are respectively disposed on diametrically opposite sides of the pivotal mounting of the jaws.

In testimony whereof I afIiX my signature.

SAM TPILSON. 

